This paper provides previously unpublished drill core and mapping evidence of the spatial relationship between regional dolomitization and Mississippi Valley-type (MVT) mineralization in the midcontinent of the United States. Dolomitization is discussed for several key carbonate units and their contained MVT mineralization. This more complete picture of the relationship between regional dolomitization and mineralization provides constraints on models for MVT mineralization and serves as an exploration guide for new deposits.